Some of the major goals in car industry are to reduce the weight and size of the cars by reducing the mechanical parts and combining them into smaller electrical system to increase the fuel economy. One way to achieve part of this goal is to use an Interior Permanent Magnet (IPM) machine as an Integrated Starter Alternator (ISA) system. In this thesis, we have accomplished two considerable improvements in IPM machine design for starter-alternator applications: ?rst, a reduction in the amount of the magnet used in machine and as a result a reduction in the total cost and secondly, an increase in the amount of the produced power in generation mode by improved design of three-layer permanent magnet on the rotor. And also, in this thesis, the Lumped-Parameters Model (LPM) is used for calculation of Q and D-axis inductances of three-layer Interior Permanent Magnet (IPM) machine, considering all details of flux barrier and air bridges of rotor and also the effect of saturation in central posts and stator core. Q and D-axis inductances are used for calculation of the average torque. To validate the model, results are compared with the Finite Element Analysis (FEA) results for a candidate IPMS machine. At last, a novel objective function is proposed for optimization of a three-layer IPM machine’s main parameters for use in 42 V ISA applications. The Optimization problem is then solved by the help of the Genetic Algorithms. Besides fulfilling the standards proposed by the Consortium, we have succeeded in increasing the starting torque and the power at high speed (6000rpm) beyond the measures proposed by the Consortium. In this thesis, a combination of Lumped-Parameters Model (LPM), quasi-Poissonian's equations and Conformal Mapping (CM) methods for predicting radial and tangential air gap flux density of Interior Permanent Magnet Synchronous Machine (IPMSM) is presented. In the proposed method, LPM is used for calculation of saturation and flux leakage. Quasi-Poisson's equation is used for forming radial and tangential flux density in slotless stator and finally CM is used to account for slot effect. To validate the method, results are compared with Finite Element Method (FEM) results for a candidate IPMSM. Keywords: Integrated Starter-Alternator (ISA), Interior Permanent Magnet Machine, Sensitivity Analysis, Genetic Algorithms
